Audio Science Review (ASR) Forum

Reviews, Technical Articles, Hardware Teardowns and Measurements of Audio Products

This is a measurement and comparison of JDS Labs USB OL DAC against the NWAVGUY's Objective DAC (also sold by JDS Labs). I also compared it to my reference budget DAC, the Topping D30. See my measurements of Objective Rev b DAC here:

And topping D30:

The JDS Labs OL DAC comes with USB-input variant at $99 which is what I purchased. And another with Toslink optical input pushing the price a whopping $40 more to $139. The Objective DAC sells for $129 which is the same price as Topping D30. But topping is a lot more feature rich with Toslink and S/PDIF inputs.


As you see in the above picture, the OL DAC improves on the Objective DAC with the addition of linear external DC input at 15 volts....
This is a hardware teardown and analysis of Topping D30 USB DAC. No doubt many of you have read my review of the D30 and know that it is my current favorite for a budget DAC ($129). There seems to be two revisions of this DAC out there so this will outline the unit I tested.

Four hex screws releases the back panel allowing the board to easily slide out without much adventure:

Topping D30 USB DAC Top Board Teardown.jpg

The board is clean with no modifications, soldering issues or any problems visible. No, you don't want to "eat of it" but for a value-oriented product, I see nothing wrong with it. Here is the revision of the board by the way:

This larger than normal budget DAC board sizes affords very good separation between the digital and analog side. Connectors are nicely spaced out which should reduce crosstalk. On top of that, there is a nice...
This is a detailed measurement and review of iFi iPurifier. This is a device that is advertised to clean up your coax S/PDIF signal from all ills including the common flu to audio distortions. It is a tiny little box the size of a thumb drive:

Not shown is the fact that it actually needs external power and iFi ships it with their switching wall-wart "iPower" power supply.

This is not a filter device but rather, one that receives digital data over S/PDIF, buffers it (puts it in memory) and then retransmits it. iFi has a nice block diagram of it on their site...
This is a review of Gustard U12 which converts USB input to S/PDIF, Toslink, AES/EBU and I^2S. The U12 retails for $170 shipped from Amazon as of this writing. I will be comparing it to Audiophilleo 1 (about $500), Fiio E10K ($76) and Melodious-Audio MX-U8 ($269). Sadly my Berkeley Alpha USB is broken so I can't test against it even though it is at much higher price point.

Gustard U12.jpg
The Gustard U12 is for people who have existing DACs and would like to add USB connectivity to it. The device has very good functionality with both consumer S/PDIF and AES/EBU...
Time for measurement and review of another budget DAC: the Hifime Sabre 9018 USB audio DAC. It retails for $80 shipped from Amazon. The closest device I have to it is the Fiiio E10K USB audio DAC which costs nearly the same at $76 on Amazon. Click to see the detailed review of Fiio E10K.

The Hifime comes in one of the lowest budget packages I have of any DAC. It is a tiny, plastic unit with permanently attached 3-4 inch USB cable and a 3.5mm headphone jack. It has a sole red LED light indicating it is on. Even the plastic package it came...
No doubt you all are familiar with audiophiles attempting to make their systems better with dedicated grounding systems for their audio equipment. Incredible amount of myth and wrong intuition is involved in such motivations and endevour, sometimes leading to very unsafe electrical systems that are not compliant with electrical safety code.

I was online and got prompted by youtube to watch this video by Mike Holt. Not sure how many of you know him but his is the most famous electrician I know. He has had an online community for seemingly forever and they argue almost as much as we do about audio! Anyway, here he is giving a talk I think for other electricians on what grounding is, and is not. Because it is a trade talk, it may be a bit challenging at times to follow but it is still a very well done presentation. He goes over key principles that are gotten wrong by audiophiles and electricians alike. And walks through the scenarios where dangerous conditions are created.

This is a hardware review of FX-AUDIO DAC-X6 USB DAC. For measurement and listening tests go to this article:

As noted in that review, this is an ultra low cost $58 DAC and headphone amplifier. They provide the overall block diagram thusly:

And that matches what is inside:


I have indicated with arrows the flow of signals. Following the USB input, we go into Via VT1603 USB interface. The digital data is then handed to Crystal Semiconductor CS8416 which is also the S/PDIF interface. The provides the serial interface to the heart of this device, the Cirrus Logic CS4399 DAC which costs about $6 in volume. The analog output then gets buffered through Ti/Burr Brown OPA2134. From there, this path splits. One goes to the rear RCA jacks and the other, to TI6120...
This is a (very) detailed measurements of FX-Audio DAC-X6 audio DAC and headphone amplifier. It also includes my listening impressions as usual. The FX-Audio DAC-X6 retails for just $58 shipped from Amazon:


Comparisons will be made against Fiio E10K which retails for $78 and Topping D30 DAC ($120). See my review and comparison of those products here: For the second part of this review, I also include the comparison to Exasound E32 DAC ($3,400 retail):

When I was close to finishing the review, I was under the impression that this was a $120 DAC or more. Imagine my...
A recent discussion in the review of Schiit Modi 2 reminded me that I was planning to do a hardware teardown of it. As reminder, the Schiit Modi 2 is a low cost ($120 shipped) USB DAC.

Audio is captured through the USB port and output on those pair of RCA jacks. The only thing unusual is that "E/S" switch that puts the DAC either in 24/96 mode or supports higher resolution to 192 KHz (different USB classes). It is an ill-intended feature especially since Windows 10 Creator Edition no longer requires drivers for either mode.

The unit is simply designed but uses a very hefty gauge of formed sheet metal which gives the unit nice weight to sit on the desk unlike many budget dacs, Screws are threaded which is nice and easily open and expose what is inside. The silver color is utilitarian and is not going to...
This is a thread to make it easier to find reviews and measurements of DACs, players, audio tweaks, etc. It is in reverse chronological order (newest first). I will update as I do more reviews.